The total number of overlapping $p$-orbitals present in cycloheptatrienyl cation is

Assuming the bond direction is along the $z$-axis,which of the following overlaps of atomic orbitals of two atoms $(A)$ and $(B)$ will result in bonding?
$I$. $s$-orbital of $A$ and $p_x$-orbital of $B$
$II$. $s$-orbital of $A$ and $p_z$-orbital of $B$
$III$. $p_y$-orbital of $A$ and $p_z$-orbital of $B$
$IV$. $s$-orbital of both $(A)$ and $(B)$

Considering the $x$-axis as the internuclear axis,which of the following will not form a sigma $(\sigma)$ bond and why?
$(a)$ $1s$ and $1s$
$(b)$ $1s$ and $2p_{x}$
$(c)$ $2p_{y}$ and $2p_{y}$
$(d)$ $1s$ and $2s$

How and when is a $\pi$-bond formed by the overlapping of orbitals?

The angle between $p$-orbitals is ......

The number of $\sigma$ and $\pi$ bonds present in an ethylene molecule is respectively: